Method of preparing metal stock and apparatus therefor



Feb.-4, 1 936. TEMPUN 2,029,800

METHOD OF PREPARING METAL STOCK AND APPARATUS THEREFOR 'Filed June 22,1954 2- Sheets-Sheet 1 Z A j 24 if; Z6 20 2/ 25 /7 VENTOR Rm Limp/m Feb.4, 1936. R. 1.. TEMPLIN- 2,029,800

METHOD OF PREPARING METAL STOCK AND APPARATUS THEREFOR Filed June 22, 1934 2 Sheets-Sheet 2 IN VENT OR Ema/d A imp/m Patented Feb'. 4, 1936METHOD OF PREPARING METAL STOCK AND APPARATUS THEREFOR Richard L.'lcmplin, New Kensington, Pa, as-

signor to Aluminum Company of America, Pittsburgh, Pa, a corporation ofPennsylvania Application June 22, 1934, Serial No. 1313'" Claims.(01.78-63) The invention relates to metal working and in particularconcerns the preparation or improvement of forging stock or of metalstock in genera 5 l In the metal working arts recognition has beenaccorded to the beneficial effects of working in relation to grainrefinement and improvement in mechanical properties of metal.Inseparable from the advantages which may be said to result from theworking methods commonly employed,

as in rolling or drawing, are certain inherent disadvantages. Perhapsone of the most important of these is represented by the phenomenongenerally referred to as the production of directional 5 properties inthe metal. Thus it is well known that in the case of rolled shapes, forexample, the tensile strength willbe greater in the direction of rollingthan transversely thereto. Many attempts have been made to avoid orminimize the directional eflect of rolling and kindred workingoperations but, so far as I am aware, none of the methods now known tothe art are completely effective; and in some cases they are of doubtfulvalue.

The designs of roll passes and of forging dies are illustrative of themeans commonly employed to work the metal in such a way as to tendtoward refinement of the grain structure and the elimination ofdirectional properties. The improvement obtainable by such expedients isquite limited, however, and is largely dependent on size and shape ofthe metalstock which is used, in relation to the size and shape of theproduct or intermediate product which is to be fabricated.

It is an object of the present invention to provide a method andapparatus for preparing metal stock which is characterized bysubstantial freedom from directional properties and which show in thisrespect a far greater improvement than is obtainable by any of themethods which heretofore have been employed. Another object is toprovide apparatus for preparing metal stock characterized by animprovement in mechanical properties and, more particularly, by anincreased fatigue limit. I

A more specific object of my invention is to provide apparatus forpreparing special aluminum stock characterized by freedom fromdirectional properties and by an attendant improvement in physicalproperties in all directions, with a marked improvement in fatiguelimit.

A further object of the invention is to provide apparatus for preparingmetal stock which apparatus comprises an attachment which can be used inconnection with conventional extrusion presses, and a method ofpreparing metal stock by a combination of die expressing and die forgingsteps which can be performed with ordinary extrusion machinery used inconjunction with my special attachment. Other objects and advan- 5 tageswill appear from the following description in which reference will behad to the accompanying drawings.

In the drawings, Fig. 1 represents a cylindrical extrusion billetadapted to be processed in the 10 apparatus and by the method which isto be described. Fig. 2 is a vertical sectional view taken through thelongitudinal axis of the cylinder of an extrusion press and associatedstructure, with the parts shown in the position which they occupy 15 atthe end of the first step of the method. Fig. 3 is a vertical sectionalview also taken on the longitudinal axis of an extrusion press andshowing a fragment of the cylinder of the press and associatedstructure. The parts are shown in the 20 position which they occupyafter the extruded billet formed in the first step of the method hasvbeen ejected from the die assembly, with the die assembly withdrawn topermit ready removal of the billet.

Fig. 4 is a fragmentary vertical sectional view of the extrusion presscylinder and a portion of the die assembly in which, however, the diehas been replaced by a solid block. The parts are. shown in the positionwhich they occupy at the 30 beginning of the second step of the method.Fig.

5 is a view similar to Fig. 4 butshowing the plunger of the presspartially advanced and with the other parts in the position occupieddurin an intermediate stage of the second step of the 35 method. Fig. 6is a view similar to Figs. 4 and 5 but with the parts in the positionoccupied after the completion of the second step and during removal ofthe processed billet and the sleeve from the cylinder of the press.Throughout the de- 40 scrlption of the drawings similar referencenumerals will be used to indicate the same parts.

The apparatus and method which I have devised are adapted to work orknead the metal by first efiecting a reduction in the cross sectional 5area of the starting billet by extrusion, and thereafterupsetting theextruded billet by what will be referred to as a die forging operationwhich brings the billet back to substantially its original form. Themethod broadly relates to that de- M scribed in mycopending'application, Serial No. 731,876, and the present invention isconcerned with a novel apparatus and method for carrying out the generalprocess described in connection with Figs. 4 and 5 of the copendingcase.

Referring more particularly to Fig. 2, cylinder may be of conventionalconstruction and are .merely representative of typical extrusion pressdesign. It is usual to provide means for heating the cylinder of thepress and, as shown, this means is afforded by an outer casing 4 whichis recessed at 5 to provide heatln': chambers. The casing 4 in theconstruction shown forms part of the frame 6which carries the dieassembly bed plate I, and the die assembly which is indicated generallyby the reference numeral 8.

The die assembly 8 may also be of conventional construction and, in thedesign shown, comprises the tool container 9 with an integral die holderI0 provided with a conical recess to receive the die II. The die II isheld in place by a back-up piece I2 which, in turn, is locked in placeby the die block I3. The forward face of the die I I fits into a conicalrecess I4 formed in the end of the cylinder I, and the entire dieassembly 8 is locked in position by means of a wedge block I5 which isshaped in the form of an inverted U through the center of which theextruded billet may pass. An actuating rod I6 is attached to the wedgeblock I5 and forms a part of mechanical means (not shown) for raisingand lowering the wedge block. A movable portion I I of the usual run-outtable is secured, as at I8, to the container 9 of die assembly 8. Iprefer that the movable table ll be arranged for mechanical operation bya cylinder and plunger arrangement, such as customarily provided inconnection with extrusion press equipment, so as to provide a convenientmeans for withdrawing the die assembly into the position shown in Fig.3.

In order that the metal, after passing through the die II, may befurther processed in accordance with the second step of my method, it isquite essential that the extruded billet be straight and true. I haveprovided for this by means of a run-out guide in the form of a tube orpipe I9 which passes through concentric apertures 20 in the toolcontainer 9, die block I3 and back-up member I 2. At its inner end thetube I9 is seated in the counter-boredportion 2I of the die II, abuttinga shoulder at the end of the counterbore. Tube I9 is aligned with theaxis of the extruded billet and supported at its outer end by anyconvenient means, as by the bracket 22, which may be secured to thetable I! by screws 23. The end of the extrusion plunger is shown at 24.A follower 25 is provided, which has a diameter substantially equal tothat of the inside of the cylinder, and the end 'of the plunger 24 isarranged to bear against the follower 25.

The extruded billet is shown at 26 and will have a collar 21 formed bythe end metal which does not pass through the die. At the end of theextruding operation the wedge block I5 is raised into the position shownin Fig. 3, and the die assembly 8 is withdrawn to permit removal of theextruded billet 26. It will be found convenient to provide an auxiliaryplunger 28 which can be rigidly mounted in the position shown in Fig. 3or may be arranged to be swung out of the way as desired. As the dieassembly 8 is withdrawn from the end of the cylinder I the extrudedbillet 26 is brought into abutting relationship with the end of theplunger 28 and pushed back through the die I I, after which it dropsdown or is lowered onto the transverse rails 29 in position to be rolledor lifted out of the way. During or after the initial movement of dieassembly 8 away from the end of cylinder I, the plunger 24 may I duringthe upsetting operation.

be further advanced into the position shown in Fig. 3 to push follower25 out of the cylinder I.

In the next step of the process, which will be described with referenceto Figs. 4 and 5, the end of the cylinder I is closed by means of asolid block 30 which is held in the tool container 9 in lieu of the dieII and which is provided with a conical portion 3I seating against theconical end I4 of cylinder I. A sleeve 32, the interior diameter ofwhich conforms to the diameter of the extruded stock 26 and the exteriordiameter of which corresponds to the interior diameter of the extrusionpress cylinder I, is slipped over the extruded stock 26 and the sleeve,with the stock therein, is slid into the cylinder I from the right, asviewed in Fig. 4. I prefer that the extruded billet 26 be turned end forend so that the collar 21 thereof will abut the block 30 which closesthe end of the cylinder I. A follower 25', similar to the follower 25described in connection with Fig. 2 but smaller in diameter so that itwill conform with the interior diameter of sleeve 32, is placed in theend of the sleeve behind the billet 26- and the plunger 24 brought tobear against this follower 25'. It will be observed that by using theseparate followers 25 and 25' it is possible to use the same plunger 24in both steps of the method which is of advantage where both steps areto be performed in the same extrusion press.

-As pressure is applied by means of the plunger 24 acting against thefollower 25', the extruded billet 26 is caused to conform with the wallsof the cylinder I. The sleeve 32 is allowed to be pushed to the right,as viewed in Figs. 4 and 5, as the metal flows'around the inner end 33of said sleeve. forging, the billet 26 is brought back to the originalform shown in Fig. 1, or to substantially that form. Fig. 5 illustratesthe die forging operation and shows the parts in the position occupiedduring an intermediate stage of this operation. At the completionthereof the upset or die forged billet will appear as indicated by thedotted lines 34 in Fig. 5 and the full lines in Fig. 6.

The die assembly 8 is again withdrawn to open the end of cylinder I andcoincidentally with this movement of the die assembly or following suchmovement, plunger 24 is further advanced into the cylinder to eject theupset billet 34, allowing it to drop down on the die assembly bed plateI. The sleeve 32 may also be ejected from the cylinder I in the samedirection by withdrawing the In this operation of upsetting or die.

plunger 24 to the right sufficiently to allow the follower 25' o bereplaced again by follower 25 so that when the plunger 24 is againadvanced to the left the sleeve 32 will be pushed out of the cylinder Iand will in turn engage the end of the upset billet 34 and push itfarther to the left, as indicated in Fig. 6, to allow its ready removal.

It will readily be appreciated by those skilled in the metal working artto which the present invention appertains, that many variations can bemade, both in the apparatus which has been described and in thesuggested manipulation of such apparatus, while continuing to utilizethe general teaching afforded by my novel method and apparatus as hereinpublished. For example, it may be found desirable to remove the collar21 after the first step of the method and I have found it sometimes tobe of advantage as otherwise the edge of the collar may be detached andfollow the sleeve 32 in its movement to the right Likewise it would bepossible to remove the extruded billet 26 by pushing it back through thecylinder I instead of out to the left, or, after the upsetting through adie to reduce its diameter, placing the extruded stock within a sleeveconforming with the interior of the cylinder and the exterior of theextruded stock. andapplying pressure to the end of the extruded stock toupset it and cause it to conform with the walls of the cylinder whileallowing the sleeve to be pushed out as the metal flows around the innerend thereof; and the essential steps in such method comprise providing acylinder with a closed end, placing therein a sleeve, and within thesleeve 2. billet, and applying pressure to the end of the billet toupset it and cause it to conform to the walls of the cylinderwhileallowing the sleeve to be pushed out as the metal flows around theinner end thereof. The essential feature of the apparatus resides in.the slidable sleeve and its arrangement in a cylinder with a closed endand a plunger slidable within the cylinder and within the sleeve,providing means for die forging a cylindrical billet to increase thecross sectional area thereof. I

The cycle of extrusion and upsetting may be repeated any number of'timesin accordance with the method described in my copending applica= tionhereinabove referred to. After removal of the sleeve 32 in the mannerwhich'has been described in connection with Fig. 6 it is only necessaryto replace the solid block 30 with the die II and repeat the operationsdescribed. I

*prefer to produce a number of extruded billets 26 at one time andthereafter conduct a series of upsetting operations, in orderto avoidthe necessity for interchanging the die II and block 30 and thefollowers 25 and 25' any more often than is necessary. Obviously thefirst step might be performed on one press and the second step onanother, although in the foregoing description it hasbeen assumed thatthe same press would be usedfor all operations.

In order to enable those skilled in the art to readily practice theinvention I have described specific embodiments and employed specificlan-- guage, but I have no intention of excluding equivalents or minorvariations of the invention set forth.

I claim: v I 1. In the method of preparing metal stock the step whichcomprises upsetting a metal billet by forces acting parallel to thelongitudinal axis 'of the billet until it has assumed an upset form ofincreased cross sectional area throughout substantially its entirelength.

2. Method of preparlng metal stock which comprises extruding a metalbillet through a die to reduce the cross sectional area thereof, guidingthe extruded stock as it issues from the die to preserve its alignment,upsetting the extruded stock by forces acting parallel to thelongitudinal axis thereof while restricting the flow of metal in alateral direction to cause the said extruded stock initially to assumeat one end a form of increased cross sectional area while initiallyretaining the form of reduced cross sectional area throughout the majorportion of its length, and

'allowing the initial increase in cross sectional area to progressthroughout the length of the extruded stock until it has assumed anupset form of increased cross sectional. area throughout subreduce thecross sectional area thereof, guiding the extruded stock as it issuesfrom the die to preserve its alignment, upsetting the extruded stock byforces acting parallel to the longitudinal axis thereof whilerestricting the flow of metal in a lateral direction to cause the saidextruded stock initially to assume at one end a form substantially equalin cross sectional area to that of the original metal billet whileinitially retaining the form of reduced cross sectional area throughoutthe major portion of its length,- and allowing the initial increase incross sectional area to progress throughout the length of the extrudedstock until it has assumed an upset form of cross sectional areasubstantially equal to that of the original billet throughoutsubstantially its entire length. v

4. Apparatus for preparing metal stock com-' prising a cylinder forlimiting the upsetting flow of a metal billet, one end of said cylinderbeing closed, an elongated sleeve arranged within the cylinder, said,sleeve adapted for receiving a metal billet therewithin with one endabutting the closed end of said cylinder, the inner end of said sleevebeing initially closely adjacent said closed end of the cylinder, andmeans for applying pressure to the other end of said billet to cause itto conform with the walls of the cylinder while allowing the sleeve tobe pushed out of the cylinder as the metal flows around the inner end ofthe sleeve.

5. Apparatus for preparing metal stock which comprises a cylinder forlimiting the upsetting flow of a metal billet, one end of said cylinderbeing closed, a sleeve slidably arranged within the cylinder, saidsleeve adapted for receiving a metal billet therewithin with one endabutting the closed end of said cylinder, the inner end of said sleevebeing initially closely adjacent said closed end of the cylinder, andmeans including a substantially fiat-ended plunger slidable within saidsleeve for applying pressure to the other end of said billet to cause itto conform with the walls of the cylinder while allowing the sleeve tobe pushed out of thecylinder as the metal flows around the inner end ofthe sleeve.

- RICHARD L. TEMPLIN.

